Even by Washington standards, Sen. Bob Menendez’s ties to a former aide, a South Florida donor and an overseas port deal that could benefit the two looks unusually cozy, ethics watchdogs say.

Menendez’s relationship with Dr. Salomon Melgen drew national scrutiny after federal agents last week raided the West Palm Beach eye clinic of Melgen, the senator’s longtime friend and donor.

Last year, as Melgen poured money into Menendez’s reelection efforts, the New Jersey Democrat advocated for a mammoth Dominican Republic port-security contract held by one of Melgen’s companies, called ICSSI.

A former Menendez aide, one-time Miami resident Pedro Pablo Permuy, is slated to be a top officer for ICSSI, Melgen’s cousin has said.

Permuy also runs a business advocacy group, the United States-Spain Council, which Menendez co-chairs. It’s supported by another Melgen company and a host of well-heeled special interests on Capitol Hill.

“This web of relations raises eyebrows,” said Meredith McGehee, policy director for the Washington-based nonpartisan Campaign Legal Center.

McGhee said it’s fairly typical for a former Congress member and aide to work closely together when both leave Congress.

“But what distinguishes this relationship is that the senator is still in office,” McGehee said. “And there’s not just one link. There are many: Menendez, the former staffer, the donor, the business and the nonprofit business group.”

Complicating the situation is the wide-ranging nature of the FBI’s interest in Menendez and Melgen.

When FBI agents raided Melgen’s office, they were joined by inspectors from the U.S. Department of Health and Human Services, which is investigating potential Medicare fraud.

That probe is parallel to the FBI investigation examining the ties between Melgen and Menendez.

The FBI began examining the two after a shadowy tipster began emailing claims that Menendez and Melgen consorted with Dominican Republic prostitutes, some of whom were said to be underage.

Both men deny the charges, with Menendez telling reporters this week that the emails were a “smear.”

The tipster who leveled the allegations, starting in the spring of 2012, did so by email and likely used a pseudonym. He refused to meet with investigators.

One tip that did pan out: Menendez did use Melgen’s private plane and failed to report it or pay for it in 2010, breaking Senate ethics rules.

Only after a New Jersey Republican Party ethics complaint was filed did Menendez’s staffers check his schedule and, they said, determine Menendez had taken two trips on the plane that he should have reported as a gift or paid for.

Menendez cut a $58,500 check to Melgen, the senator’s office said. Menendez flew only three times on Melgen’s jet and properly accounted for it once, staffers said, adding that the senator has paid for personal trips to the Dominican Republic via commercial flights other times. But they did not disclose the dates or number of visits.

When the New York Times first reported Permuy’s involvement in the ICSSI deal, Permuy tried to downplay his involvement in a brief email to the newspaper.

Permuy, a Belen Jesuit Preparatory school graduate who attended the University of Miami, has since stopped answering his phone or emails.